Pressure control valve for fluid operated mechanism



R. ERLING 2,044,777

PRESSURE CONTROL VALVE FOR FLUID OPERATED MECHANISM June 23, 1936;

Filed March 17, 1934 5 Sheets-Sheet l MoTor /a firirli!!! a Q ,0, 7 Z w. V 7 w M 1 m U y 3 x I Q A M Q m z. w

ATTORNEY R. ERLING June 23, 1936.

PRESSURE CONTROL VALVE FOR FLUID OPERATED MECHANISM Filed March 17, 1934 3 Sheets-Sheet 2 MoTor Pump Ralph Erling INVENTOR ATTO EY June 23, 1936. R ERLlNG 2,044,777

PRESSURE CONTROL VALVE FOR FLUID OPERATED MECHANISM Filed March 17, 1934 3 Sheets-Sheet 3 Rlph Erling INVENTOR ATTOR Y Patented June 23, 1936 "PRESSURE CONTROL VALVE FOR FLUID OPERATED MECHANISM Ralph Erling, Alexandria, Va.

Application March 17, 1934 Serial No. 716,145

15 Claims.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) This invention relates to mechanism operated v by fluid pressure and more particularly to by-pass I heretofore necessary with installations of this nature;

To provide a mechanical assembly adapted for use with a combined by-pass and relief valve.

In the drawings:

Figs. 1 and 4 are sectional views of an embodiment of my invention wherein the housing for the by-pass and relief valves is mounted on the ram of the hydraulic mechanism;

Figs. 2 and 3 are in general similar to Fig. 1 but disclose the use of the same valves for both by-pass and relief purposes;

Figs. 5 and 6 illustrate applications of my inventions to two rams;

Figs. 7 and 8 show a by-pass shuttle valve mounted on the ram, the latter having in addi tion spring loaded relief valves;

Figs. 9 and 10 show valve constructions similar to those of Figs. 7 and 8, respectively, but with the valve housing separate from the ram and with arms carried by a rudder post to unseat the by-pass valve.

While the present invention will be described in connection with hydraulic steering gear, it is to be understood that its usefulness is not limited thereto but extends to any and all kinds of hydraulic apparatus wherein pressure control of the nature herein described is necessary.

In hydraulic steering gears it is necessary to have two types of valves, one to relieve the oil pressure at any rudder angle if the pressure exceeds a predetermined magnitude, and the other to prevent the rudder being forced into the hardover stops under power at any pressure up to the aforesaid predetermined magnitude. The present disclosure sets forth the combination of these two,

motor it, both of well known construction, is connected to cylinders l4 and I5 by pipes l9 and 20, respectively, to supply fluid to and withdraw fluid from the cylinders.

Mounted upon the ram l3 between cylinders l4 and I5 is a valve ,housing .2| having in it a plurality 'of interconnectible chambers whereof one is directly connected to cylinder M by a. duct 22 in the rain and another is likewise connected to cylinder I5 by duct 23. Disposed in positions PATENT OFFICE to be forced against their seats by pressure in the cylinders as transmitted through ducts 22 and 23 are by-pass valves 24 and-25, preferably loaded by light springs 26, and having stems 2'| and 28, respectively, extending outwardly through the valve housing, each of which stems passes through an aperture in a fixed member 29 and has at its outer end a head 30 of greater area, than the aperture in the fixed member. In housing 2|, positioned to be subjected to pressure from the ducts 22 and 23, respectively, are relief valves 3| and 32, loaded by springs 33.

It is apparent that when pump I1 is supplying fluid under pressure to cylinder M if at any time the pressure rises above the predetermined maximum fixed by loading spring 33 valve 3| will be unseated and fluid will pass through the opening controlled thereby and traverse the housing to valve 25, which will be unseated by the fluid thus transmitted and such fluid will pass into duct 23 and thence into cylinder l5 due to the fact that the pump is withdrawing fluid from the last named cylinder. However, if the pressure at no time rises sufficiently to unseat the relief valve 3|, as the crosshead |2 approaches the hard-over stop l6 head 3| on stem 21 will contact the adjacent fixed member 29 and unseat by-pass valve 24, thereby relieving the pressure in cylinder M to cylinder I5 and checking further movement of the crosshead toward the stop I6. The valves 25 and 32 will operate in the manner above described for valves 24 and 3| when I5 is the pressure cylinder.

Fig. 2 discloses a valve housing 34 mounted upon the ram l3 having in it valves 35 and 36 loaded by springs 31 disposed to be unseated by pressure through the ducts 385'and 39, respectively, in excess of the maximum set by the loading springs. In addition, these valves have stems 40 and 4|, respectively, extending through the housing 34 to contact fixed members 42 near the end of movement of the ram in one direction or the other. Therefore, if the valves 35 and 33 do not function as relief valves during the course of any stroke, that one which is approaching a fixed member 42 is opened by contact of its stem 40 or 4|, as the case may be, with the adjacent fixed and 46 are operated as by-pass valves by pull on the stems 41 and 48, respectively, due to contact the valve housings not normally visi in the plane of the figures have been indicated n dotted lines to make clear the construction of these housings. 1

Fig. 4 is very similar to Fig. 2 except that the 10 valves I and 52 are by-pass valves only, the

relief valves subjected to pressure simultaneously with the by-pass valves being designated '2 and It, respectively. The by-pass valves II and B2 are pushed open by contact of the heads on stems 55 and I! with the fixed members II.

Figs. 5 and 6 illustrate the application'of my invention to an installation having two rams II and I! connected to rudder post II by links ill and ii and yoke 82. As is common in this art, the pump 62 driven by motor N is connected through pipes 05, 68 and I1, '8 to diagonally opposite cylinders, 88, Ill and 'H', 12 to cause the torques exerted by the rams 52 and I8 upon rudder post ii to be additive. The adjacent cylinders 25 69 and II are connected together by a valve housing it wherein are disposed by-pass and relief valves 14 and II to control the fluid pressure in the respective diagonally opposite pairs'of cylln ders. If the pressure in cylinders 09 and I becomes unduly high, the valve 14 is unseated thereby and the fluid is transferred through check valve 16 into cylinder ll. Likewise, excessive pressures in cylinders 1| and 12 are relieved through the valves 15 and 11. The valves 14 and 15 are caused to function as by-pass valves by contact of the members is and 19 carried by rams 58 and 59, respectively, with the heads 80 on valve stems 8| and 82. The mechanism of Fig. 6 is in general similar to that of Fig. except that the valves 83 and 84 are by-pass valves only, the cooperating relief valves being respectively 85 and I6.

In Fig. 7 the housing 81 is mounted on ram li and the two chambers therein are in communication with cylinders I4 and I! through ducts 22 and 22. The two chambers in the housing Il may be placed in communication through an opening in which is seated a shuttle valve 82 having stems 89 and 80 extending from the ends thereof to unseat the valve when brought into contact with fixed members 8| carried by the cylinders. It is apparent that, owing to the great difference between the cross sectional area of astem 88 or 90 and that of the median portion of valve 88 between the heads 92 and 83 thereof, fluid under pressure in one of the cylinders will exert a diflerential pressure on the outer face of the head 92 or 93, as the case may be, and so seat shuttle valve 88 as to prevent transfer of fluid from one cylinder; to the other through the opening between the chambers and housing 81. However, as the stroke of the ram vnears completion the stem 90, as shown for purpose of illustration in Fig. '7, will contact the ner as in Fig. 2. In Figs. ii'and' 8 the portions of member 9i and unseat valve 88, thus by-passing pipes ill and ill. Shuttle valve III is mounted in a passage between the chambers ofhousing I! and has stems-I00 and ill extending outwardly to be contacted by arms Ill and I mounted upon or actuated by the rudder post II or rudder crosshead l2 to unseat the valve substantially'at the end of movement of the rudder "crosshead toward the stops I8 and so by-pass the fluid and check the movement of the ram i2. The device shown in Fig. 10 is in general similar to that disclosed in Fig. 9 but reliefvalves ill and iii are provided to prevent excessive pressures, being applied in the system, and the chambers of the valve housing l'l communicate direct- 1y with the outlets of the pump, upon which'the housing is mounted. It is believed that the operation of the several modifications of my invention will be clearly apparent from the foregoing.

The invention described herein may be manufactured and used by or for theGovernment of 9 the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

I claim: I

1. Fluid pressure mechanism, comprising a pair of cylinders, a piston in each cylinder actuatable by fluid pressure therein, a valve housing having a chamber in communication with each cylinder to receive fluid from the cylinder, there being a passage between said chambers, a valve to close 3 said passage, loading means to hold said valve seated until the pressure in the chamber exceeds a predetermined magnitude and then permit unseating of the valve by such pressure, a second valve disposed to close a second passage 3. between said chambers and to be held seated by the fluid pressure, a stem connected to said'sec- 0nd valve and extending through the wall of the chamber and an element disposed to contact said stem and unseat the second valve substantially 4 at the end of travel of the piston in one direction by relative movement of the valve andthe ele ment due to operation of the piston.

2. Fluid pressure mechanism, comprising apair of cylinders, a ram having an end disposed in each .5 of said cylinders to act as a piston therein, a valve housing having two chambers, each of which is in communication with one of said cylinders, and a passage between said chambers, a shuttle valve disposed to control transfer of fluid 60 through said passage, a stem extending from each end of said valve, and means relatively movable with respect to said valve by motion of said ram to contact said stems and unseat said valve.

3. Fluid pressure mechanism, comprising a pair 55 of axially aligned cylinders, a piston in each, a valve housing operatively connected to both of said pistons to move as a unit therewith, said housing having in it two chambers with a passage I between, there being in said pistons ducts com- 00 municating with said chambers and said cylinders,

a shuttle valve disposed in said passage, a stem extending from each end of said valve, and means relatively movable with respect to said valveby motion of said pistons to contact said stems and unseat said valve.

4. Fluid pressure mechanism, comprising an actuatable member, fluid pressure operated means to actuate said member in opposite directions; and means to control the flow of fluid in said means including a housing having two chambers with a passage between them, a shuttle valve operatively disposed in said passage, a stem extending from each end of said valve, and means connected to said member to be moved thereby to contact said stems and unseat said valve substantially at the end of movement of said member in each direction.

5. Fluid pressure mechanism, comprising a pair of cylinders, a piston in each cylinder, said pistons being connected to move as a unit, a valve housing mounted between said pistons to move therewith, said housing having two chambers respectively communicating with said cylinders and a passage between said chambers, a shuttle valve.

actuatable member, fluid pressure operated means to actuate said member in opposite directions; and means to control the flow of fluid in said means including a housing having two chambers and a passage between said chambers, a shuttle valve in said passage, a stem extending from each end of said valve, means operatively associated with said member to contact said stems and unseat said valve substantially at the end of movewaive. in said passage, a stem extending from each end of said valve, and means operatively associated with said member to contact said stems and unseat said valve substantially at the end of movement of said member in each direction.

8. The combination with a rudder crosshead, of a ram connected thereto, cylinders in which the ends of said ram are operable as pistons; and a fluid transfer system connected to both said cylinders including a valve housing having two chambers and a passage between said chambers, a shuttle valve in said passage, a stem extending from each end of said valve, and means operable by said crosshead to contact said stems and unseat said valve substantially at the end of movement of said crosshead in each direction,

'9. The combination with an oscillatable member,,of two pistons connected to move as a unit 5 and operatively connected to said member, cylinders in which said pistons are respectively operable; and fluid transfer means connected to both said cylinders including a valve housing having two chambers and a passage between said chamhere, a shuttle valve in said passage, a stem extending from each end of said valve, and means operable by said member to contact said stems and unseat said valve substantially at the end of movement of said member in each direction.

10. The combination with an oscillatable member, of two pistons connected to move as a'unit and operatively connected to said member, cylinders in which said pistons are respectively operable; and fluid transfer means connected to both said cylinders including a valve housing having two chambers and a passage between said chambers, a shuttle valve in said passage, a stem extending from each end of said valve, means operable by said member to contact said stems and unseat said valve substantially at the end of movement of said member in each direction, and a relief valve operatively disposed to control the maximum pressure in each of said chambers, each of said relief valves being unseatable by pressure in its respective chamber in excess of a predetermined magnitude.

11. The combination with an oscillatable member, of two pistons connected to move as a unit and operatively connected to said member, cylinders in which said pistons are respectively operable, means to supply fluid under pressure to one of said cylinders while simultaneously withdrawing fluid from the other, alternately, a housing having in it two chambers with a passage between them, said chambers being respectively in communication with said cylinders, a shuttle valve to and means to unseat said valve substantially at the end of movement of said member in each direction.

12. In combination, two cylinders, a piston operable in each, said pistons being connected together to move as a unit; and a fluid transfer system interconnecting said cylinders including a single valve housing, a relief valve in said housing to relieve pressures in each of said cylinders in excess of a predetermined maximum, 8. by-pass valve in said housing to permit flow of fluid from each of said cylinders to the other, and means functioning substantially at the end of outward movement of each piston in its cylinder to open control transfer of 'fluid through said opening, 20

the by-pass valve controlling the flow of fluid from the cylinder in which the piston is moving.

13. In combination, two cylinders, a piston operable in each, said pistons being connected together to move as a unit; and a fluid transfer system interconnecting said cylinders including a 40 single valve housing, a relief valve in said housing to relieve pressures in each of said cylinders in excess of a predetermined maximum, a shuttle valve in said housing unseatable to permit flow of fluid from one of said cylinders to the other adapted to be held seated by pressure in either of said cylinders, and means functioning substantially at the end of outward movement of each of said pistons in its cylinder to unseat said bypass valve and permit flow of fluid from the cylinder in which the piston is moving outwardly.

14. In combination, two pistons connected together to move as a unit, cylinders in which said pistons are respectively operable; and fluid transfer means connected to both said cylinders including a bi-chamber valve housing mounted to move with said pistons, there being a passage between the chambers of said housing, a valve in said passage seatable by pressure in either or said cylinders, and means to unseat said valve subpistons are respectively operable; and fluid transfer means connected to both said cylinders ineluding a valve housing mounted to move with said pistons, and valve-mechanism in said housing operatively associated with said pistons to control transfer of fluid from one of said cylin- 7o ders to the other through said housing.

' RALPH ERLING. 

